Mercury switch for railways and the like.



No. 889,963. PATENTED JUNE 9, 1908. R. PPEIL. MERCURY SWITCH FOR RAILWAYS AND THE LIKE.

APPLICATION FILED JAN 6, 1908.

UNITED STATES PATENT OFFICE.

ROBERT PFEIL, OF GRUNEWALD, NEAR BERLIN, GERMANY, ASSIGNOR TO SIEMENS &

HALSKE, A. G., OE BERLIN, GERMANY, A CORPORATION OF GERMANY.

MERCURY SWITCH FOR RAILWAYS AND THE LIKE.

Specification of Letters Patent.

Patented June 9, 1908.

Application filed January 6, 1908. Serial No. 409,585.

To all whom it may concern:

Be it known that I, Ronnncr PFEIL, a subject of the German Emperor, and residing at Bcymestra'sse 28*30, Grunewald, near Berlin Germany, have invented certain new and useful Improvements in Mercury Switches for Railways and the Like, of which. the following is a specification.

The present invention relates to railwaysignal operating devices and has for its object improvements in mercury switches for use with the same.

In means which enable a traveling train to act on iixed working devices, accidental action on the devices as well as a breakdown of the intended aeration must be prevented as much as possi le.

Known means in which mercury switches operated by a v'ehicle passing along a rail are employed alone or in combination with in sulatod rails fuliill these conditions to a certain extent. Nevertheless when the level of the mercury is not at the correct height it may happen that either a detent or lock is prematurely released, or a detent and signal are not released at all.

N ow an important object of the present invention is to obtain av higher degree of certainty of working by arranging a second place where the circuit is closed in a mercury switch which is o aerated by a bending rail, by means of which second contact the position of the mercury in the switch can be controlled. lhis control can be cll'ected by means of audible or visible signals, the release of which is dependent on the second contact and indicates that the level of the mercury has passed the limits when the intended action of the mercury switch no longer takes place. If this control merely consists in a signal, such. as a colored disk or a bell, which is perceptible, visible or audible to the pointsm an or signal-man, it still remains left to the conscicntiousness of the pointsman to rectify at the right time the defect which is indicated by the signal. if the controlling current is used however for making conditions of working which are necessary for the unimpeded passage of the train, the points man or signalman is compelled to report the indication at once. In this manner a higher degree of safety is obtained. Such conditions of working are made for example by placing a signal in various positions.

in order that the invention may be clearly understood, reference is made to the acc0mpanying drawing in which two embodiments are represented diagrammatically by way of example, and in which Figure 1 shows a. device which comes into operation behind the last axle of the train, whereas Fig. 2 represents a device which comes into action under the first axle, and Figs. 3 and 4 show part of the means in Fig. 2 in modified positions.

In both examples represented in the drawing the train is to set the signal .(13) automatically at stop, and is to make its release thereafter into the lineclear position dependent on a block apparatus being worked.

Referring to Fig. 1 in the drawing, 1 denotes the locking rod of a block apparatus, 2 a contact controlled by it, and 3, 4, 5 a press button lock which is influenced by a spring 6, armature 7 and electromagnet 8; by depressing the rod 1 the contact-lever 5 is brought into the position in which it is shown in the drawing, in which it keeps the switcharm 9 closed and the catch 4 in the locked position.

14 is the winding of an electric signal-wing coupling of known kind for the signal-wing 13. The relay consisting of the parts 15 to 18 makes the block-apparatus and the signal dependent on the passage of the train in a manner which is known in itself, but which is described again hereafter.

The mercury switching device has a receptacle or switch-box 21 attached to the rail 20, and besides the current-supply device 22 which dips into the cup 23 and pipe 24 there is a second current-supply device 26 in addition, the point of which is continuously below the normal surface 27 of the mercury. and 28 are small outlets, 29 is the, pressure chamber, 30 the diaphragm and 31 the plunger of the known mercury switch operated by a bending rail.

l V hen the rail 20 is traveled over by a vehi cle and mercury is forced by the diaphragm through pipe 24 into cup 23, the following circuit is closed:battery 10, conductor 11, arm 9, winding 15, conductor 35, currentsupply device 22, mercury in pressure chamber 29, conductor or earth 32, terminal 12, and back to battery 10; the armature 16, which is attracted by the magnet 15 of the relay, connects the two magnet windings 15 and 8 on one side to the insulated rail 19 by means of the contacts 17 and 18, whereby, on accountof the following circuit, '5. e.: battery 10, conductor 11, arm 9, magnet winding 15, contact 18, conductor 36, insu- 5 lated rail 19, through the axle of the train to rail 20, conductor 32, terminal 12, battery 10,the relay-magnet remains operative independent of the state of the mercury switch, and whereby, after the last axle of 13 the train has passed, the magnet 8 is also ener ized and the press-button lock released by t e following circuit, t. e.:battery 10, conductor 11, arm 9, magnet windin 15, contact 18, conductor 36, insulated ra l 19, 13 conductor 37, contact 17, magnet winding 8,

terminal 12 and battery 10,-the contactlever 5 which is released by the armaturelever 7" bein snapped upwards by the spring 6. The hit erto closed signal-coupling cirgo cuit, i. e.:battery 10, conductor 11, arm 9,

arm 2, conductor 33, magnet winding 14, conductor 34, current-supplying device-*26, mercury 29, conductor 32, terminal 12, and battery 10is thereby also broken at the contact 9 and the signal-wing 13 goes back automatically into its normal or stop position. On account of the connection of the signalcoupling 14 through the conductor 34 with the second device 26 for closing the circuit of the mercury switch, the quantity of mercury which is present and'the height of the same is controlled which is of great importance for the safety of Working the line. If, for example, the coupling were connected, as is usual, simply directly to earth, at its battery-terminal 12 for example, and if there was an insufficient quantity of mercury in the switch-box 29, when-the train passed 40 over this section of the line the contact 22, 29

would not be closed and thus the signal could not be set to stop. In the above described arrangement in accordance with the present invention on the contrary, the signal could not be placed at line clear in the case of' a deficiency of mercury, as the above described signal-coupling circuit would be interrupted at the control contact 26.

As is represented in Figs. 2 to 4, the same control can also be obtained in a device which returns the signal into its normal position under the action of the first axle.

With the exception of the insulated rail and the relay, Fig. 2 contains all the principal parts shown in Fig. 1. The second contact-pin 26 dips into a pipe 39 connecting with the pipe 24 and chamber 29, which arrangement is different from that in Fig. 1.

When a train travels past the part of the 0 rails where this mercury switch 1s situated,

as indicated in Fig. 3, a considerable quantity of mercury is forced by the first wheel 41 from the receptacle 29 through the ipes 24 and 39 into the upper chamber 40, w rerecs by the contact 22 is c osed, whereas the contact 26 remains closed. The following circuit in F ig. 2, 'i.e.:battery 10, conductor 11, .arm 9, magnet winding 8, conductor 38, current-supply device 22, mercury 29, rail 20, conductor 32, battery terminal 12 and 743 battery 10,-causes the release of the pressbuttonlock and the signal to be placed at stop by' interrupting at contact 9 the signal-coupling circuit, 11. e.:battery 10, conductor 11, arm 9, arm 2, conductor 33, magnet winding 14, conductor 34, contactpin 26, mercury 29, rail 20, conductor 32, battery terminal 12, and battery 10.

As soon as the first wheel leaves the rail .over the mercury switch, the level of the g mercury in the receptacle 29 at once sinks so low that the contact 26 is also interrupted (Fig. '4), as the mercury which is in the chamber 40 can flow back only slowly through the small opening 28 into the recepg5 tacle 29. In this manner the signal-coupling circuit is broken at a second place so that the signal is returned to the ,stop position even in case the press-button releasing device breaks down. Moreover, in 0 this form the position of the level of the mercury is controlled in the normal position (Fig. 2) by the signal-coupling circuit.

The electrical arrangement of the pressbutton locking magnet protects, generally speaking, from the danger of the mercury being too high in the receptacle of the inercury switch, and this magnet in this case prevents the signal being set at line clear.

An electromagnet can be used to revent o premature release on account of the evel of the mercury being too high, which magnet releases the signal-lever only when it is without current, it being temporarily inserted between the current-supplying pm 22 or a 5 third similarly arranged contact and the pole 11 of the battery. The same purpose can be served by an interrupter in the circuit of the relay-magnet or of the pressbutton locking device, which interrupter can only be closed after the level of the mercury has been controlled.

What I claim as my invention and desire to secure by Letters Patent is:-

1. A mercury switch, for operation by a vehicle passing along a railway, comprising a receptacle containing mercury, a diaphragm in the receptacle contacting the mercury, a rail-actuated plunger for moving said diaphragm, and a circuit-closing device in said receptacle adapted to be contacted by the mercury, in combination with a second circuit-closing device in said receptacle normally contacting the mercury, for the purpose of controlling the level of the mercury in said receptacle.

2. A mercury switch, for operationby a vehicle passing along a railway, comprising a receptacle containing mercury, a diaphragm in the receptacle containing the mercury, a

.rail-actuated plunger for moving said diaphragm, and a contact in said receptacle adapted to be contacted by the mercury, in

' combination with a second contact in'said receptacle normally contacting the mercury, andelectric means for controlling a signal electrically connected with said second contact and the mercury, the arrangement being such that the circuit through the second contact must be closed in order to make conditions of workingxnecessary for the unimpeded passage of a ve icle.

'3. A mercury switch, for operation by a vehicle passing along a railway, comprising a rece tacle containing mercury, a diaphragm in t e receptacle containing the mercury, a rail-actuated plunger for moving said diaphragm, and a contact in said receptacle ada ted to be contacted by the mercury, in com ination with a second contact in said receptacle normally contactin the mercury, a si nal coupling, electric book-apparatus mec anism, and a battery for operating the signal coupling in series with one another and electrically connected with said plunger, whereby a current cannot be sent through said signal coupling to operate the signal unless the second contact contacts the mercury in the receptacle.

LA mercury switch, for operation by a vehicle assing along a railway, comprising a switchox containing mercury, partitions in said box dividing the same into compartments communicating with one another and one above the other, a diaphragm closing one end of the lowest compartment, a rail-actuated plunger on said diaphragm and a contact in the highest compartment normally above the mercury, in combination with a second contact in a compartment normally contacting the mercury, whereby when said plunger is temporarily depressed mercury is temporarily sent into contact with the former contact and then flows away from the second contact, as set forth.

5. A mercury switch, for operation by a vehicle passing along a railway, comprising a receptacle containing mercury, a pipe carrying a cup connecting with the bottom of the receptacle, said cup having a small hole in the same, a diaphragm closi one end of the receptacle, a rail-actuated p unger on said dia hra m and a contact in said cup norma ly a ove the mercury, in combination with a second pipe communicating with the bottom of the former pipe and a second contact in the latter pipe normally contacting the mercury, the arrangement being such ROBERT PFEIL.

Witnesses HENRY HASPER, WOLDEMAR HAUPT. 

